Últimos itens adicionados do Acervo: Proceedings Nature

Nature é uma das mais prestigiosas e antigas revistas científicas do mundo: sua primeira edição é de 4 de novembro de 1869. Entre as inúmeras descobertas científicas publicadas na Nature estão a dos raios X, da estrutura em dupla hélice do ADN e o buraco na camada de ozônio.

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‣ Lyme Borreliosis During Pregnancy

András Lakos; Norbert Solymosi
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
One of the authors (AL) presented a poster on 34 pregnancies of maternal Lyme borreliosis (Lb) in 1995. It was striking that untreated Lb associated with higher probability of adverse outcome but the number of patients were small and the statistical power was low. We have recently published a paper on 95 maternal Lb and the outcome of their pregnancies. Since the closure of the database for that manuscript the number of the pregnant women with Borrelia infection observed in our Centre increased to 124, and the statistical analysis strengthened our previous doubtful observations and reached significant results in important aspects by now. This series is the largest study to date on this topic. Treatment was administered parenterally to 87 (70%) women and orally to 25 (20.0%). Infection remained untreated in 12 (10%) pregnancies. Adverse outcomes were seen in 7/87 (8%), 9/25 (36%), 8/12 (67%), of the parenterally, orally treated and untreated women, respectively. In comparison to patients treated with antibiotics, untreated women had a significantly higher risk of adverse pregnancy outcomes (OR: 11.62, p<0.001). Mothers treated orally comparing to iv. treatment had an increased chance (OR: 6.28) to have an adverse outcome (p=0.001). In the adverse pregnancy outcome...

‣ SBML Reaction Finder: Retrieve and extract specific reactions from the BioModels database

Maxwell L. Neal; Herbert M. Sauro
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Summary: The SBML Reaction Finder (SRF) application leverages the deep semantic annotations in the BioModels database to provide efficient retrieval and extraction of individual reactions from SBML models. We hope that the SRF will be useful to quantitative modelers who seek to accelerate their modeling efforts by reusing previously published representations of specific chemical reactions. Availability and Implementation: The SRF is open source, coded in Java, and distributed under the Mozilla Pubic License Version 1.1. Windows, Macintosh and Linux distributions are available for download at http://sourceforge.net/projects/sbmlrxnfinder.

‣ Highly Efficient Gene Expression in B Lymphocytes Mediating by Lentivirus Vector

Akira Tempaku
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Gene transduction and expression efficiencies among several type cell lines were compared by using vesicular stomatitis virus-glycoprotein (VSV-G) pseudotyped human immunodeficiency virus type-1 (HIV-1) based lentivirus vector. Large discrepancies of the efficiencies were shown among them. B lymphocytes showed high susceptibility of gene transduction and expression, while other cell lines marked lower potential. Variable gene transduction strategies have been assessed to apply immunological therapies. This study showed that B lymphocytes had facilities enough to support the gene transduction and expression by lentivirus vector. Our result suggested that the lentivirus vector would be a powerful tool to express exogenous genes in B lymphocytes.

‣ The hypothalamic genesis of obesity

Daniel Oscar Belluscio
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
Português
The theories on obesity genesis shifted during the past years from the simple conception of "just overeating" to data supporting the diencephalic origin of the disease. Summarized findings on this issue are displayed.

‣ Data Mining of the Coffee Rust Genome

David Octavio Botero-Rozo; William Giraldo; Alvaro Gaitan; Marco Cristancho; Diego M. Riaño-Pachon; Silvia Restrepo
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
The genomes of nine isolates of _Hemileia vastatrix_, the causal agent of coffee leaf rust were sequenced by Illumina and 454. Quality control, cleaning and _de novo_ assemblies of data were performed. Since isolates were obtained from the field and it is not possible to produce axenic cultures of _H. vastatrix_, MEGAN software was used to evaluate contamination levels and to select contigs with fungal similarities. Mitochondrial contigs were identified and annotated by comparing this assembly against the _Puccinia_ genome. Furthermore, two transcriptomes from isolates of _H. vastatrix_ were assembled to complement the genomic data.

‣ FAIRE-seq data analysis of Chlamydomonas reinhardtii under carbon deprivation

David Urbina-Gómez; Flavia Vischi Winck; Bernd Müller-Röber; Diego Mauricio Riaño-Pachón
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
For the genome-wide identification of nucleosome depleted regions under carbon deprivation, we analyze an available set of data from an assay of formaldehyde-assisted isolation of regulatory elements followed by sequencing (FAIRE-seq). Mapping to the sequenced nuclear genome of C.reinhardtii, followed by the identification of the enrichment-sequenced fragments was performed. We examined the location of these fragments relative to annotated genes. The related genes were associated to the corresponding Gene-Ontology (GO), for an evaluation of over-representate GO categories. Some genes, link with functions or locations, that have been previous described, indicating the success of the method finding carbon-metabolism related fragments.

‣ Colour reverse learning and animal personalities: the advantage of behavioural diversity assessed with agent-based simulations

Adrian G. Dyer; Alan Dorin; Verena Reinhardt; Marcello G. P. Rosa
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Foraging bees use colour cues to help identify rewarding from unrewarding flowers, but as conditions change, bees may require behavioural flexibility to reverse their learnt preferences. Perceptually similar colours are learnt slowly by honeybees and thus potentially pose a difficult task to reverse-learn. Free-flying honeybees (N = 32) were trained to learn a fine colour discrimination task that could be resolved at ca. 70% accuracy following extended differential conditioning, and were then tested for their ability to reverse-learn this visual problem multiple times. Subsequent analyses identified three different strategies: ‘Deliberative-decisive’ bees that could, after several flower visits, decisively make a large change to learnt preferences; ‘Fickle- circumspect’ bees that changed their preferences by a small amount every time they encountered evidence in their environment; and ‘Stay’ bees that did not change from their initially learnt preference. The next aim was to determine if there was any advantage to a colony in maintaining bees with a variety of decision-making strategies. To understand the potential benefits of the observed behavioural diversity agent-based computer simulations were conducted by systematically varying parameters for flower reward switch oscillation frequency...

‣ Cocaine self-administration in the mouse: A low-cost, chronic catheter preparation

Matthew B. Pomrenze; Michael V. Baratta; Brian A. Cadle; Donald C. Cooper
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Intravenous drug self-administration is the most valid animal model of human addiction because it allows volitional titration of the drug in the blood based on an individual’s motivational state together with the pharmacokinetic properties of the drug. Here we describe a reliable low-cost mouse self-administration catheter assembly and protocol that that can be used to assess a variety of drugs of abuse with a variety of protocols. We describe a method for intravenous catheter fabrication that allows for efficient and long-lasting intravenous drug delivery. The intravenous catheters remained intact and patent for several weeks allowing us to establish stable maintenance of cocaine acquisition. This was followed by a dose response study in the same mice. For collaborators interested in premade catheters for research please make a request at www.neuro-cloud.net/nature-precedings/pomerenze.

‣ In vitro shoot regeneration from cotyledon of redgram

Telugu Raghavendra; Palagiri Sudhakar; K Balakrishna Reddy; Keerthi Venkaiah; Putta Latha; Tollamadugu NVKV Prasad; Lakkireddi Prasanthi
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Pigeonpea is one of the most popular legume grains in the world, especially in the Indian sub-continent. Keeping in view the importance of the crop, an efficient protocol for rapid in vitro plant regeneration from cotyledon of redgram has been reported in this paper. The concentraion of the hormones played an important role in shoot and root regeneration.

‣ Complex Systems Biology of Organisms

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Complex Systems Biology models and theories are axiomatically defined in terms of concrete categories and organismic supercategories (OS) to include both complete self-reproduction of logically defined pi-entities founded in Quine's logic and dynamic system diagrams subject to both algebraic and topological transformations. Mathematical models of complex organisms are expressed in terms of category theory and organismic supercategories (OS). OS theories have applications in: Bioinformatics, Developmental Biology, Genomics and Molecular Cell Biology

‣ Category of Metabolic-Replication Systems in Biology and Medicine

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Metabolic-repair models, or (M,R)-systems were introduced in Relational Biology by Robert Rosen. Subsequently, Rosen represented such (M,R)-systems (or simply MRs)in terms of categories of sets, deliberately selected without any structure other than the discrete topology of sets. Theoreticians of life's origins postulated that Life on Earth has begun with the simplest possible organism, called the primordial. Mathematicians interested in biology attempted to answer this important question of the minimal living organism by defining the functional relations that would have made life possible in such a minimal system- a grandad and grandma of all living organisms on Earth.

‣ Cancer Clinical Trials Optimization and Pharmacogenomics

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
A critical overview of recent clinical trials in cancer is presented focused on signaling pathways blockers or inhibitors with a view to developing successful clinical trials employing personalized cancer therapies. Rational, pharmacogenomic strategies in cancer trials should be adopted that include specific molecular targeting based on adequate data for, and detailed modeling of, cancer cell genomes, modifications of cancer signaling pathways and epigenetic mechanisms. Novel translational oncogenomics research is rapidly expanding through the application of highly sensitive and specific advanced technology, research findings and computational tools and complex models to both pharmaceutical and clinical problems. Multiple sample analyses from several recent clinical studies have shown that gene expression data for cancer cells can be employed to distinguish between tumor types as well as to predict outcomes. Potentially important applications of such results are individualized human cancer therapies or, in general,'personalized medicine' that will have to be validated through optimally designed clinical trials in cancer. A Human Cancer Genomes and Epigenetics Project is proposed that can provide the essential data required for the optimal design of clinical trials with the goal of achieving significant improvements of the survival rates of cancer patients participating in clinical trials for advanced cancer stages. The results of such a six-year Human Cancer Genomes and Epigenetics Project should also greatly aid with the accelerated...

‣ Near Infrared Reflectance Spectroscopy (NIRS) Determination of Isoflavone Contents for Selected Soybean Accessions

I. C. Baianu; Jun Guo; Tiefeng You; Randall L. Nelson
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
Português
Soybean isoflavones are of considerable interest in relation to their possible health effects in human diets. The rapid and economical determination of soybean isoflavone concentrations is essential for the investigation and development of soybean health foods as well as the selection of soybean seeds with optimal isoflavone levels for such foods. Fourier transforms near infrared reflectance spectroscopy (FT-NIRS) calibrations were developed for the rapid and cost-effective analysis of isoflavones in soybean seeds. FT-NIRS measurements were carried out in quadruplicate for 50 soybean lines selected from the USDA Soybean Germplasm Collection. The selected soybean seeds provided a wide range of isoflavone concentrations (from 0.3 to 6.0 mg/g) that is necessary for development of high-quality calibrations. Laboratory reference values of isoflavone composition were obtained by HPLC analysis of extracted soybean powders. Single soybean seeds were selected for each standard sample and were cut in half in order to avoid screening of the isoflavones NIR absorption bands by the seed coat. For comparison purposes, measurements were also made on soybean powders of the same samples. FT -NIR spectra were collected with a spectral range from 4000 to 12000 cm-1 at a resolution of 8 cm-1 on a Perkin-Elmer Spectrum one NTS spectrometer model. This spectrometer is optimized for high sensitivity analysis of single seed composition...

‣ Nitric oxide synthase in skeletal muscle fibres of patients with type 2 diabetes

Karla Punkt; Katharina Kandt; Andreas Oberbach; Volker Adams; Igor Buchwalow; Matthias Blueher
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Muscle-derived nitric oxide (NO) mediates fundamental physiological actions on skeletal muscle including glucose uptake into muscle cells. Recently, we have shown that the altered glucose metabolism in skeletal muscle of patients with type 2 diabetes (T2D) is associated with changes in the metabolic profile of individual muscle fibres, but fibre-type specific changes in NO synthase (NOS) expression in skeletal muscle of T2D patients remain to be elucidated. Here we investigated fibre-type related NOS expression in vastus lateralis muscle of T2D patients compared with healthy individuals with normal glucose tolerance (NGT). Cytophotometrical assay and Western blotting did not reveal any quantitative differences between NOS expression in muscles from NGT and T2D subjects. Positive NOS immunoreactivity in vastus lateralis of T2D patients was found to be associated with fast-oxidative glycolytic (FOG) muscle phenotype. This indicates that NOS expression in T2D patients correlates both with skeletal muscle fibre type distribution and the activity of oxidative and glycolytic enzymes.

‣ Theory of the Origin, Evolution, and Nature of Life

Erik D. Andrulis
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
Life is an inordinately complex unsolved puzzle. Despite significant theoretical progress, experimental anomalies, paradoxes, and enigmas have revealed paradigmatic limitations. Thus, the advancement of scientific understanding requires new models that resolve fundamental problems. Here, I present a theoretical framework that economically fits evidence accumulated from examinations of life. This theory is based upon a straightforward and non-mathematical core model and proposes unique yet empirically consistent explanations for major phenomena including, but not limited to quantum gravity, phase transitions of water, why living systems are predominantly CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur), homochirality of sugars and amino acids, homeoviscous adaptation, the triplet code, and DNA mutations. The theoretical framework proves the unity of macrocosmic and microcosmic realms, validates predicted laws of nature, and solves the puzzle of the origin and evolution of cellular life in the universe.

‣ Metabolic, Replication and Genomic Category of Systems in Biology, Bioinformatics and Medicine

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Metabolic-repair models, or (M,R)-systems were introduced in Relational Biology by Robert Rosen. Subsequently, Rosen represented such (M,R)-systems (or simply MRs)in terms of categories of sets, deliberately selected without any structure other than the discrete topology of sets. Theoreticians of life’s origins postulated that Life on Earth has begun with the simplest possible organism, called the primordial. Mathematicians interested in biology attempted to answer this important question of the minimal living organism by defining the functional relations that would have made life possible in such a minimal system- a grandad and grandma of all living organisms on Earth. Genomic systems are also considered as molecular realizations of (M,R)-system subcatgeories.

‣ A Critical Evaluation of Clinical Trials in Cancer and Pharmacogenomics

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
A critical overview of recent clinical trials in cancer is presented focused on signaling pathways blockers or inhibitors with a view to developing successful clinical trials employing personalized cancer therapies. Rational, pharmacogenomic strategies in cancer trials should be adopted that include specific molecular targeting based on adequate data for, and detailed modeling of, cancer cell genomes, modifications of cancer signaling pathways and epigenetic mechanisms. Novel translational oncogenomics research is rapidly expanding through the application of highly sensitive and specific advanced technology, research findings and computational tools and complex models to both pharmaceutical and clinical problems. Multiple sample analyses from several recent clinical studies have shown that gene expression data for cancer cells can be employed to distinguish between tumor types as well as to predict outcomes. Potentially important applications of such results are individualized human cancer therapies or, in general, ‘personalized medicine’ that will have to be validated through optimally designed clinical trials in cancer. A Human Cancer Genomes and Epigenetics Project is proposed that can provide the essential data required for the optimal design of clinical trials with the goal of achieving significant improvements of the survival rates of cancer patients participating in clinical trials for advanced cancer stages. The results of such a six-year Human Cancer Genomes and Epigenetics Project should also greatly aid with the accelerated...

‣ Determination of Soybean Oil, Protein and Amino Acid Residues in Soybean Seeds by High Resolution Nuclear Magnetic Resonance (NMRS) and Near Infrared (NIRS)

I. C. Baianu; Tiefeng You; Doina Costescu; P R. Lozano; Valentin Prisecaru; Randall L. Nelson
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
Português
A detailed account is presented of our high resolution nuclear magnetic resonance (HR-NMR) and near infrared (NIR) calibration models, methodologies and validation procedures, together with a large number of composition analyses for soybean seeds. NIR calibrations were developed based on both HR-NMR and analytical chemistry reference data for oil and twelve amino acid residues in mature soybeans and soybean embryos. This is our first report of HR-NMR determinations of amino acid profiles of proteins from whole soybean seeds, without protein extraction from the seed. It was found that the best results for both oil and protein calibrations were obtained with a Partial Least Squares Regression (PLS-1) analysis of our extensive NIR spectral data, acquired with either a DA7000 Dual Diode Array (Si and InGaAs detectors) instrument or with several Fourier Transform NIR (FT-NIR) spectrometers equipped with an integrating sphere/InGaAs detector accessory. In order to extend the bulk soybean samples calibration models to the analysis of single soybean seeds, we have analized in detail the component NIR spectra of all major soybean constituents through spectral deconvolutions for bulk, single and powdered soybean seeds. Baseline variations and light scattering effects in the NIR spectra were corrected...

‣ A database of orthologous exons in primates for comparative analysis of RNA-seq data

Ran Blekhman
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
RNA-seq technology facilitates the study of gene expression at the level of individual exons and transcripts. Moreover, RNA-seq enables unbiased comparative analysis of expression levels across species. Such analyses typically start by mapping sequenced reads to the appropriate reference genome before comparing expression levels across species. However, this comparison requires prior knowledge of orthology at the exon level. With this in mind, I constructed a database of orthologous exons across three primate species (human, chimpanzee, and rhesus macaque). The database facilitates cross-species comparative analysis of exon- and transcript-level regulation. A web application allowing for an easy database query: http://giladlab.uchicago.edu/orthoExon/

‣ Virtual screening for NS5B inhibitors of Hepatitis C virus

Amjesh R; Achuthsankar S. Nair; Sugunan V.S.
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
Hepatitis C Virus (HCV) infection is a serious cause of chronic liver disease worldwide with more than 170 million infected individuals at a risk of developing significant morbidity and mortality. To date there is no effective drug for the treatment or vaccine to prevent this infection. The present study aims to discover novel inhibitors which target an allosteric binding site of RNA dependent RNA polymerase enzyme of HCV. A structure based virtual screening of Zinc database by computational docking and the post docking analysis of energy calculations and interactions followed by ADMET studies were conducted. Our study revealed 10 compounds which has more potential than the existing inhibitor to be considered as lead compounds.